1. Field of Invention
The present invention relates generally to excavating devices and more specifically to submarine excavating devices.
2. Description of the Prior Art
Examples of the most pertinent patents found are U.S. Pat. Nos.: 3,153,290; 3,434,551; 3,763,580; 3,874,462.
U.S. Pat. No. 3,434,551 shows a core sampler comprising a bouyant rig for supporting coring operations underwater. The bouyant rig comprises a float and a bottom weighted stand interconnected by a guide wire. A core barrel slidably extends through the weighted stand. A piston slidably mounted in the core barrel penetrates the ocean bottom. Suction is provided by a hydraulic pump mounted on the bottom weighted stand.
U.S. Pat. No. 3,153,290 discloses a submarine sampler comprising a jet pump having a jet pump nozzle, a downward nozzle for shaving and a horizontal nozzle for cutting sediment. A flexible pipe is connected to a floating operation deck which is capable of moving the water pump until it reaches the gravel layer.
U.S. Pat. No. 3,874,462 shows an excavation apparatus comprising a core barrel slidably mounted inside a guide tube for deploying and recovering the core barrel. The guide tube has two openings, an entrance and an exit for the core barrel to move through the guide tube passageway after having taken samples.
U.S. Pat. No. 3,763,580 is directed to an apparatus for dredging in deep ocean comprising an elongated hollow conduit and a dredging tool connected to the conduit pendulously supported from a floating vessel. The conduit is rotated to rotate the dredging tool along the ocean floor. Material loosened by the dredging tool is lifted upward through the hollow conduit by an air lift mechanism in which pressurized air is injected into the conduit to force materials to flow upwardly.
A number of problems remain in the prior art that are addressed by the present invention. With the exception of U.S. Pat. No. 3,153,290, the prior art disclosures require either guide wires or stands of some sort to help deploy the elongated barrel means for excavating ocean material. The present invention does not require any guide wires or stands to maintain its vertical in ocean swells. The plural flotation tanks effectively maintain the vertical of the invention, precluding a need for additional supports. U.S. Pat. No. 3,153,290 requires a floating stand hovering over the area to be excavated as the conduits connected to the pump originate from this floating stand. The present invention does not require a special floating stand. Hoses attached to the conduits allow the surface vessel a range of flexibility in choosing its position. The surface vessel need not hover directly over the area to be excavated. The present invention is equipped with a depth sensing device to relay the depth of penetration to the surface vessel. None of the prior art disclosures reveal such a device. The present invention further comprises an airlift mechanism especially designed to assist the collection of ocean sediment in depths greater than 150 feet. This mechanism injects air into the flow of sediment, thus lowering the specific gravity of the sediment, aiding the upward flow of collected sand and seawater. None of the prior art disclosures reveal such a mechanism.
The present invention consists of an inner pipe within a pipe held rigidly together by screws. This design aids in maintaining the rigidity of the sampler against the force of pressurized water encountered in the ocean. No additional sidewalls are necessary to shield the collection conduit as the outer pipe serves to shield the inner pipe against collapse.
The present invention is relatively inexpensive to manufacture in comparison to prior art excavation devices. The principal components of the invention can be assembled from pipe fittings with only the throat piece of the jet pump requiring machining and casting.
No special rigging apparatus is required by the surface vessel in deploying the invention in the ocean. As a result, any small commercially available vessel may adequately perform excavating operations. The design of prior art devices precludes small vessels from engaging in excavating operations requiring vessels equipped with winches and other specially designed equipment.